A watermark is an identifying image or pattern in paper. The watermark may appear as various shades of lightness or darkness when viewed caused by variations in thickness or density variations of the paper. Watermarks can be used for security to discourage counterfeiting, for identification purposes, and the like. Watermarks can be used on postage stamps, currency, government documents, and the like.
Watermarks can currently be created using processes such as a dandy roll process or a cylinder mold process. The dandy roll process may impress a water-coated metal stamp onto the paper during manufacturing. The cylinder mold process may use tonal depth and creates a greyscale image. The watermark may be created by areas of relief on a roll's own surface.